All new cars should be required to have brake override systems, a key senator says at Toyota hearings.

Reporting from Los Angeles and Washington Ken Bensinger -- Momentum is building for a rule requiring automakers to install brake override systems so drivers can stop their cars during incidents of sudden acceleration, which has been blamed in the deaths of more than 50 people in accidents involving Toyota vehicles nationwide.

At a Senate Commerce Committee hearing on Toyota's sudden-acceleration problem Tuesday, Sen. John D. Rockefeller IV (D-W.Va.) said "strong legislative action," including mandates for brake overrides, is needed to protect motorists. Rockefeller, the committee chairman, also called for requiring senior company executives to personally certify that information provided to regulators is "100% correct and accurate."

The Department of Transportation is also considering a rule to mandate an override system.

"We think it is a good safety device, and we're trying to figure out if we should be recommending that," Transportation Secretary Ray LaHood told members of the committee.

At the hearing, senators slammed the National Highway Traffic Safety Administration -- overseen by LaHood's department -- for not identifying serious safety problems with Toyota vehicles earlier, saying that the agency does not have enough technical expertise to handle increasingly complex auto electronics systems and questioning whether government officials are too cozy with the industry they oversee.

Sen. Barbara Boxer (D-Calif.) and three other senators questioned whether two former NHTSA officials who went to work for Toyota influenced the government's slow response.

LaHood said they complied with legal prohibitions on contacting the agency on issues they had worked on at the agency, but said he would welcome a rule preventing NHTSA employees from going to work for automakers until at least two years after leaving the agency.

Sen. Olympia J. Snowe (R-Maine) called the agency's response to the safety issues "lethargic" and "outdated."

Senators also publicly chastised three Toyota executives who testified later for not responding more aggressively to the sudden-acceleration complaints.

But even with another round of apologies from company executives, Shinichi Sasaki, Toyota Motor Corp.'s executive vice president in charge of quality assurance and customer service, suggested that sudden acceleration was caused by driver error, such as improperly placed floor mats.

"We need to do more to consider customer expectations and real-world usage of our vehicles, even irregular use," he said. "We need to reduce the number of things we ask our customers to do correctly."

Takeshi Uchiyamada, the company's chief engineer, told senators that the company had done extensive testing on the electronic system in its vehicles and was confident it is not the cause of the sudden acceleration, which also has led to Toyota's issuing nearly 10 million recall notices worldwide.

"I want to be absolutely clear: As a result of our extensive testing, we do not believe sudden unintended acceleration because of a defect in our [electronic throttle control system] has ever happened," he said. "However, we will continue to search for any event in which such a failure could occur."

Toyota has sold 40 million vehicles with such a system, he said, but "there was not a single case" in which they could identify the electronic throttle control system as the cause of the unintended acceleration.

Uchiyamada and the other executives stressed the changes Toyota is making to improve vehicle safety and consumer confidence. They announced that a Toyota official from North America now will have a formal role on recall decisions, which previously had been made exclusively in Japan, and that former U.S. Transportation Secretary Rodney Slater would head a blue-ribbon panel of independent experts to review the company's "enhanced quality controls."

Separately, the Los Angeles city attorney's office is opening a preliminary criminal investigation of Toyota, examining a range of potentially illegal behavior, including false advertising and making unsupported assurances to Toyota owners about the safety of their vehicles.

The city became concerned about its own liability because it owns about 750 Toyota vehicles in its fleet, said Jeffrey Isaacs, deputy chief of the special operations and litigation division. And the city pension fund owns Toyota stock, he said.

The city can bring misdemeanor, but not felony, charges. Last week, Toyota disclosed that it had received a subpoena from the U.S. attorney's office in New York, indicating federal authorities are conducting a criminal investigation. The company also said it received a subpoena from the Securities and Exchange Commission office in Los Angeles.

In Washington, Rockefeller said Toyota and NHTSA failed to respond properly to a flood of complaints beginning in 2003 about sudden unintended acceleration in Toyota vehicles.